Valve assembly having a unitary valve sleeve

ABSTRACT

A valve assembly preferably including a housing having a recess and a flange face and a valve sleeve disposed within the recess. The sleeve preferably includes an annulus having an outer surface and an inner surface that defines a passageway about a central axis, the outer and inner surfaces being radially spaced from one another to define a wall. The wall has a first end portion and a second end portion axially spaced from the first end portion, and homogenous material properties from the first end portion to the second end portion. Preferably, the first end portion defines a lip for supporting the annulus in the recess and further defines a first chamber that encases at least a portion of a first support member. The second end portion preferably defines a flange portion along the outer surface for engaging the flange and further defines a second chamber that encases at least a portion of a second support member.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of flow controlvalves and the construction thereof. More specifically, the presentinvention relates to the internal components of flow control valvesincluding the elastomer sleeve that provides a sealing surface for thevalve components and connections.

Flow control valves such as, for example, knife gate valves or lineblind valves, are used to control the flow of fluids and can beparticularly well suited for use with abrasive and corrosive slurriessuch as are encountered in, for example, the mining, pulp or paperindustries. One form of gate valve known in the art includes a housingconstructed of two halves that when coupled together form the valvehousing and passageway therethrough. On opposite sides of the housingare connections for installing the valve in a pipe line, for example,the housing can be bolted to a flange end of a pipe. To control the flowof fluid through the valve, the valve includes a gate that, inoperation, translates or travels between the two valve halves. Eachvalve half defines a sleeve recess in which is disposed a valve sleeve.The valve sleeves are axially aligned to define the passageway andprovide a sealing function in the valve. To seat the valve sleeves inthe recesses, the sleeves can be configured with ridges or lips toconform to the contours of the sleeve recess. The two valve sleeves sealagainst one another when the gate is in the open configuration to allowfor fluid flow through the valve while substantially preventing fluidleakage from the valve housing. When the gate is in the closed position,the opposing sleeves seal against the gate and substantially prevent thefluid that collects against the gate from leaking from the housing. Oneexemplary valve housing and sleeve assembly includes the CLARKSON KGDWAFER STYLE SLURRY KNIFE GATE VALVE from TYCO FLOW CONTROL as shown inthe TYCO FLOW CONTROL data sheet entitled “Clarkson KGD Wafer StyleSlurry Knife Gate Valve 2” thru 24″ (2005). Other known valves and valvesleeves are shown and described in, for example, U.S. Pat. Nos.4,895,181 and 5,730,149.

Valve sleeves not only create a sealing surface between the valve gateand one another, but the valve sleeves also provide a support surface toengage the flange surfaces of the valve housing or other piping elementscoupled to the valve housing. Known valve sleeves use a two-piececonstruction in which the sleeve has a seat portion that is disposedwithin the sleeve recess of the valve housing and a separate supportdisc which snaps to the seat portion to form a flange for engagementwith the flange face of the housing. The separate support disc isgenerally sized to the pipe to which the valve housing is coupled. Inaddition, the support disc is generally made of a harder plastic orother hard material to provide a surface against which the adjoiningpipe may rub. Moreover, the material forming the support disc isdissimilar to the material of the seat portion of the sleeve.

Because the support disc is made of a hard material, its ability toprovide a tight seal between flange surfaces, in some operativeconditions, may be limited. Moreover, because the support discs areconstructed from a material different than the valve seat portion, theflange and its support disc may not be as chemically resistant as theseat portion. Accordingly, the flange and its support disc may besusceptible to long term fatigue, such as cracking or breaking Inaddition, due to the inelasticity of the hardened support disc, thesupport disc may not withstand or be resilient to over-compression bythe flange bolts coupling the valve into the piping assembly.Alternative known sleeve designs include an integrated support discportion. However, these alternative designs do not effectively addressthe issue of over-compression at the flange bolts.

SUMMARY OF THE INVENTION

A preferred embodiment of a valve sleeve for sealing a valve having arecess and a flange includes a support ring disposed about a first axis,an annular support plate disposed about a second axis, and an annulusdisposed about a third axis and having a one-piece wall continuouslyradially disposed about the third axis to define a passagewaytherethrough. The wall preferably includes a seat portion defining afirst end face of the annulus and has a lip along the wall forsupporting the annulus in the recess of the valve. The support ring ispreferably encased in the seat portion such that the support ring iscoaxial with the annulus so as to radially support the seat portion. Theseat portion further preferably defines a first radius relative to thethird axis. The wall further includes a flange portion defining a secondend face of the annulus and has a second radius relative to the thirdaxis greater than the first radius to engage the flange of the valve.The annular support plate is preferably encased in the flange portionsuch that the support plate is coaxial with the annulus so as to axiallysupport the flange portion.

The flange portion further preferably defines at least one chamberdisposed radially from the third axis having an opening disposed alongthe second end face. In a preferred embodiment, the chamber extendsaxially from the flange portion into the seat portion. In anotherpreferred embodiment, the flange portion has a first portion and asecond portion radially disposed about the first portion, the firstportion defining a first thickness to encase the annular support plateand a second portion defining a second thickness to form a gasket forsealing the flange of the valve.

The flange portion is preferably formed with the seat portion such thatthe annulus has homogenous material properties from the first end faceto the second end face. More preferably the valve sleeve has a unitaryconstruction and can further be formed from an elastomeric material.

In another preferred embodiment of the valve sleeve, the sleeve includesa wall having a first end portion and a second end portion axiallyspaced from the first end portion, the wall having homogenous materialproperties from the first end portion to the second end portion. Thewall preferably includes a first portion defining a first chamber thatencases at least a portion of a first support member and a secondportion defining a second chamber that encases at least a portion of asecond support member. The wall further preferably defines a thirdchamber extending axially from the second portion to the first portion.Preferably, the first and second chambers intersect at least a portionof the third chamber. In another preferred embodiment, the sleevefurther includes a pin plug disposed in the chamber.

A preferred embodiment of a valve assembly includes a housing having arecess and a flange face and a valve sleeve disposed within the recess.The sleeve preferably includes an annulus having an outer surface and aninner surface that defines a passageway about a central axis, the outerand inner surfaces being radially spaced from one another to define awall. The wall has a first end portion and a second end portion axiallyspaced from the first end portion, and homogenous material propertiesfrom the first end portion to the second end portion. Preferably, thefirst end portion defines a lip for supporting the annulus in the recessand further defines a first chamber that encases at least a portion of afirst support member. The second end portion preferably defines a flangeportion along the outer surface for engaging the flange and furtherdefines a second chamber that encases at least a portion of a secondsupport member.

Another preferred embodiment provides a method of forming a valvesleeve. The method can be achieved by disposing a first substrate abouta member in a mold chamber, disposing a second substrate axially spacedfrom the first substrate and about the member, and encapsulating atleast a portion of the first substrate and at least a portion of thesecond substrate within an elastomeric material so as to form a body ofunitary construction. Preferably, disposing the first substrate aboutthe member includes disposing an annular plate about the member, theplate extending radially relative to the central axis. Moreover,introducing the elastomeric material preferably includes injectionmolding of the material.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theinvention, and together, with the general description given above andthe detailed description given below, serve to explain the features ofthe invention. It should be understood that the preferred embodimentsexamples of the invention as recited in the appended claims.

FIGS. 1-4 are plan, side and cross-sectional views of a valve having avalve sleeve.

FIG. 5 is an illustrative embodiment of a valve sleeve.

FIG. 5A is a cross-sectional view of the valve sleeve of FIG. 5.

FIG. 5B is cross-sectional detailed view of the valve sleeve of FIG. 5.

FIG. 5C is an illustrative embodiment of a pin plug for use with a valvesleeve.

FIG. 5D is a plan view of the pin pug of FIG. 5C

FIG. 6 is an illustrative embodiment of another valve sleeve.

FIG. 6A is a cross-sectional view of the valve sleeve of FIG. 5.

FIG. 6B is cross-sectional detailed view of the valve sleeve of FIG. 5.

FIG. 7 is an illustrative support ring for use in a valve sleeve.

FIG. 8 is an illustrative embodiment of a ring plate for use in a valvesleeve.

FIG. 9 is an illustrative embodiment of a mold for forming a valvesleeve.

FIG. 9A is cross-sectional view of the mold of FIG. 9.

FIG. 9B is a cross-sectional detailed view of the mold of FIG. 9.

FIG. 10 is a perspective view of an alternative embodiment of valvesleeve in accordance with an embodiment of the present invention.

FIG. 10A illustrates a cross-sectional view of the sleeve shown in FIG.10 in accordance with an embodiment of the present invention

FIG. 10B illustrates a detailed cross-sectional view (identified assection B in FIG. 10A) in accordance with an embodiment of the presentinvention.

FIG. 10C is a back plan view of the valve sleeve in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION

Shown in FIGS. 1 through 4, there is provided an illustrative valve 10for use with a novel valve sleeve described herein below. The valve 10includes a housing 12 adapted to be inserted coaxially into a pipelineor other suitable fluid conduit. The housing 12 includes a port orpassageway 14 therethrough that can be axially aligned with the pipelinefor the flow of materials through the valve 10. As shown in FIG. 2, thevalve 10 is preferably formed by two similarly opposed halves that eachhave an inner surface that defines an axially extending opening. Theopening of each housing half is further preferably configured with asleeve recess to seat or receive a valve sleeve 20, including the novelvalve sleeve described herein, for sealing the valve 10. Exemplaryembodiments of the valve 10 are shown and described in U.S. Pat. Nos.3,945,604; 4,257,447; 4,688,597; 4, 895,181; 5,271,426; 5,890,700; and5,370,149, which are attached hereto respectively as Exhibits A-G andfurther incorporated by reference in their entirety to the extent theydisclose a valve configured to receive a valve sleeve. With the twohalves of the housing 12 abutted against one another, as seen in FIG. 3,the openings are coaxially aligned such that the end faces of opposedvalve sleeves 20 contact one another to define and seal the passageway14 of the valve. The valve sleeves 20 preferably have a flange portion24 extending distally to a seat portion 26 and terminating with a seatend face 22 having a lip portion 21. The lip portion 21 can include aridge 23 configured to conform to and secure the seat portion 26 in thesleeve recess of the valve housing 12. The halves of the assembled valvehousing 12 are coupled together such that the lips 21 of the seatedvalve sleeves 20 engage one another so as to form a seal about thepassageway 14 through which materials can flow. Preferably, thepassageway 14 defines a substantially circular cross-section althoughother geometries are possible such as, for example, square, oval orpolygonal provided that the opening can properly seat a valve sleeve 20to seal the valve 10 as described in greater detail herein below.

Preferably coupled to the housing 12 is a gate 16 for controlling theflow of material through the passageway 14. The gate 16 has an openposition disposed clear from the passageway 14 thereby allowing the flowof material through the valve 10 and a closed position disposed withinand perpendicular to the axial direction of the passageway 14 to preventflow of material therethrough. In moving from the open position to theclosed position the gate 16 is configured to translate between the twovalve sleeves 20. Shown in FIGS. 3 and 4 is the gate 16 moving from theopen position to a partially closed position. As the gate 16 translatesinto the closed position, the gate 16 engages the end face 22 of eachvalve sleeve 20 located to each side of the gate 16 to maintain a sealabout the valve 10. The gate 16 is preferably mounted for reciprocalmovement in and out of the passageway 14. The lower edge of the gate 16is preferably tapered to provide a relatively sharp straight knife edgeas shown to facilitate partition of the engaged lips 21 located at theseat end faces 22 of the opposed valve sleeves 20. To move the gate 16between the open and closed positions, the gate 16 further includes anactuator (not shown), preferably in the form of a pneumatic or hydrauliccylinder and piston rod arrangement. Alternatively, the actuator mayalso be a handwheel or an electric motor drive which is configured toprovide the required linear movement to the gate 16.

The flange portion 24 of the valve sleeve 20 is configured to supportthe valve sleeve 20 within the housing 12. The flange portion 24 engagesthe flange face 18 of the housing 12, as seen in the exemplaryembodiment of FIG. 1, by seating within a recess in the flange face ofthe housing 12. The flange portion 24 is further configured to engage aflange face of a piping element, for example, a pipe coupled to thevalve 10.

The inventor has discovered a new valve sleeve 20′, as seen in FIG. 5,that incorporates a flange portion 24′ and a seat portion 26′ in aunitary construction so as to provide a one-piece valve sleeve 20′ foruse with new or existing valves 10. The valve sleeve 20′ is preferablymade of an elastomeric material which allows the seat portion 26′ to beelastically resilient to the stress forces applied by the gate 16 andfurther enables the flange portion 24′ to be resilient to thecompressive forces exerted by the flange bolts or other coupling deviceholding the valve 10 in the pipe assembly.

The valve sleeve 20′ is generally an annulus or other ring shaped bodyhaving an outer surface 28′ for engaging the valve housing 12 and aninner surface 30′ to define a passageway 14′ therethrough having acentral axis A-A. The outer surface 28′ along the flange portion 24′defines a radial distance from the central axis A-A that is preferablygreater than the radial distance defined by the outer surface 28′ alongthe seat portion 26′ relative to the central axis A-A. Shown in FIG. 5Ais a cross-sectional view of the sleeve 20′. The outer and innersurfaces 28′, 30′ define the annular wall 32′ which is preferablyradially spaced and circumscribed about the central axis A-A of thepassage 14′ to form the body of the valve sleeve 20′. Because the sleeve20′ is preferably of a unitary construction, the wall 32′, as seen ingreater detail in FIG. 5B, has a proximal first end portion whichincludes the flange portion 24′ having an flange end face 19′. The wall32′ axially extends to the seat portion 26′ and terminates at a distalsecond end portion with the seat end face 22′. Because the sleeve 20′ isof a unitary construction, the wall 32′ preferably has homogenousmaterial properties extending from the flange end face 19′ to the seatend face 22′.

The outer surface 28′ along the seat portion 26′ of the wall 32′ ispreferably configured substantially similarly to the outer surface ofthe seat portions 26 in known valve sleeves, as described above, so asto be insertable into existing valves 10. More specifically, the seatportion 26′ preferably includes a lip portion 21′ at the end of thevalve sleeve to engage an interior groove within the valve housing 12 tosecure the valve sleeve in the sleeve recess of the housing 12 andfurther facilitate a sealed engagement with either an opposing valvesleeve or the gate 16. The lip portion 21 preferably includes a lockingbead or ridge 23′ disposed along the seat portion 26′. The ridge 23′ ispreferably located at approximately the midpoint of the entire axiallength L of the valve sleeve 20′ and more specifically at about 53% of Lmeasured from the flange end face 19′. The ridge 23′ further preferablydefines the radial outermost portion of the wall 32′ along the seatportion 26 and is moreover preferably configured for engaging a recesswithin the housing 12 to support the valve sleeve 20′ therein. The ridge23′ can be configured to prevent the sleeve 20′ from falling out of thehousing 12 when the valve 10 is not installed in the pipe assembly. Theridge 23′ can also prevent slurry or other material buildup that maymigrate between the valve sleeve 20′ and the housing 12.

Distal of the ridge 23′, the lip portion 21′ radially tapers toward thecentral axis A-A. Preferably, the radial taper has a first taperingportion 25′ and a second tapering portion 27′. The first taperingportion 25′ defines a first angle α relative to a line parallel to thecentral axis of the passageway 14′ and the second tapering portion 27′defines a second angle β relative to an angle perpendicular to thecentral axis of the passageway 14′. Preferably, the first angle α isabout five degrees (5°) to about fifteen degrees (15°) and is morepreferably about ten degrees) (10°). The second angle β is preferablyabout fifteen degrees (15°) to about twenty-five degrees) (25°) and ismore preferably about twenty-one to twenty-three degrees (21°-23°).

The outer surface 28′ preferably defines a continuous transition withthe inner surface 30′ of the wall 32′ to further define the lip portion21′. More specifically, the second tapering portion 27′ is continuouswith a first curved portion 34′ of the inner surface 30′. The curvedportion 34′ is preferably convex relative to the passageway 14′ todefine a curved surface for engaging either the lip portion 21′ of anopposing sleeve 20′ in the valve 10 or the flow control gate 16. Theconvex curved portion defines a radius of curvature ranging betweenabout 0.15 inches to about 0.25 inches and more preferably is about 0.19inches.

In a preferred embodiment of the valve sleeve 20′, the inner surface 30′can include additional curved portions axially continuous with thecurved portion 34′ to define a surface that can facilitate the flowthrough of material through the valve sleeve 20′ and further inhibitturbulence and/or build-up of the material. Preferably, the innersurface 30′ includes a second curved surface 36′ and a third curvedsurface 38′ continuous in series with the first curved surface 34′ so asto define a groove along the inner surface 30′. The curved surfaces canbe configured as concave or convex relative to the passageway 14′ with aradius of curvature that facilitates the flow through of material.Preferably, the second curved surface 36′ is concave and defines aradius of curvature of about 0.75 inches to about 1.25 inches and ismore preferably about 1 inch. The third curved surface 38′ is preferablyconcave and defines a radius of curvature of about 0.25 inches to about0.5 inches and is more preferably about 0.375 inches. The continuouscurved surfaces 36′, 38′ define a radial groove along the inner surface30′, and preferably circumferentially about the seat portion 26′, thatcan facilitate the flow of material through the passageway 14′ andminimize the build-up of material in the sleeve 20′.

In an alternative embodiment of the valve sleeve 20″, as seen in FIGS.6, 6A and 6B, the inner surface 30″ can include a second curved surface36″, a third curved surface 38″ and a fourth curved surface 40″continuous in series with the first curved surface 34 so as to define analternate groove along the inner surface 30″. Preferably, the secondcurved surface 36″ is convex and defines a radius of curvature of about0.30 inches to about 0.45 inches and is more preferably about 0.375inches. The third curved surface 38″ is preferably concave and defines aradius of curvature of about 0.625 inches to about 0.7 inches and ismore preferably about 0.641 inches. The inventor has discovered that thepreferred radius of curvature at the third curved surface 38″ can reducepurge from the valve 10 during cycle of the gate 16 because the curvedsurface 38″ can facilitate a rebound effect in the sleeve 20″. Thefourth curved surface 40″ is preferably convex and defines a radius ofcurvature of about 0.30 inches to about 0.45 inches and is morepreferably about 0.375 inches. The continuous curved surfaces 36″, 38″and 40″ define a radial groove along the inner surface 30′, andpreferably circumferentially about the seat portion 26″, that canfacilitate the flow of material through the passageway 14′ and minimizethe build-up of material in the sleeve 20″.

The inner and outer surfaces 28′, 30′ of wall 32′ preferably defineconstant profiles circumscribed about the central axis A-A of thepassageway 14′. The circumferentially constant profiles allow for thevalve sleeve 20′ to be inserted into the valve housing 12 withoutconcern as to the radial orientation of the sleeve 20′. Alternatively,either the outer surface 28′ or the inner surface 30′ may define a firstprofile partially circumscribed about the central axis of the passageway14′ and a second profile, different from the first, partiallycircumscribed about the remainder of the passageway 14′. For example,the curved surfaces 36′, 38′ of the inner surface may be circumscribedapproximately 180°) about the central axis A-A so as to define asubstantially semi-circular groove along the inner surface 30′.

Where the profile of the inner surface 30′ includes one or more curvedsurfaces circumscribed about the central axis A-A of the passageway 14′,the diameter of the passageway 14′ can vary in a direction along thecentral axis. The one or more diameters defined by inner surface 30′define the nominal valve size of the valve 10′. For example, where theinner surface 30′ defines an input diameter at the flange end face 19′of about six inches (6 in.) and an output diameter of about six inches(6 in.) at the seat end face 22′ with an interior groove in between ofabout 5.75 inches, the nominal size of the valve sleeve 20′ and thevalve 10 is six inches.

Located between the inner and outer surfaces 28′, 30′ of the wall 32′ isa chamber 33′ as seen for example, in FIG. 5B. The chamber 33′ islocated within the seat portion 26′ and is preferably located within thelip portion 21′ and more preferably located distal of the ridge 23′. Inaddition, the chamber 33′ is radially closer to the outer surface 28′than to the inner surface 30′. Where the dimension T is the radialdistance between the outer surface 28′ and the inner surface 30′, theradial spacing t between the chamber 33′ and the outer surface 28′ hasbeen found to be about 11.5% of thickness T for all nominal sizes ofvalve sleeve 20′. In addition, where the axial distance between flangeend face 19′ to the seat end face 22′ is the length L, the axialdistance x from the flange end face 19′ to about the center point of thecross-sectional area of the chamber 33′ is about 65% of the length L.

The chamber 33′ is configured so as to house, or more preferably encase,a substrate or stiffening element within the seat portion 26′ to provideradial resistance to, for example, shearing forces exerted by the gate16 on the valve sleeve 20′ as the gate 16 between the open and closedpositions. Preferably, the chamber 33′ is continuous about the centralaxis A-A of the passageway 14′ so as to define a ring having asubstantially circular cross-section for housing a tubular ring shapedsubstrate. Alternatively, the chamber 33′ can be any other geometry inplan and/or cross-sectionally such as, for example, rectangular or otherpolygonal shape for housing a correspondingly shaped substrate. Furtherin the alternative, a plurality of chambers can be radially disposedabout the central axis A-A of the passageway 14′ within the seat portion26′ for individually housing a plurality of stiffening elements.

The chamber 33′ is preferably substantially ring shaped for encasing astiffener ring 100 as seen in FIG. 7. The stiffener ring 100 ispreferably made from a mild steel however other steels, alloys and orcomposites could be used provided the ring demonstrated sufficientradial strength. The location of the chamber 33′ dictates the locationof the ring 100. It has been found that the particular configuration andposition of the stiffener ring 100 results in two primary advantages:(1) the ring 100 radially supports the ridge 23 and prevents the pliablesleeve material from following the gate 16 during its cycle; and (2) thestiffener ring 100 can facilitate alignment of the opposing sleeves 20′installed in the valve housing 12. As the gate 16 of the valve 10 movesdownward into the closed position, the stiffener ring 100, due to thering positions being relatively surrounded by the compressible sleevematerial, functions somewhat as a fulcrum to relieve some of the sealingcompression between the lips 21′ of the opposing valve sleeves 20′ sothat the tapered lower knife edge of the plate may more easily separatethe lips. In so doing, the sleeves move into the space surrounding thegate and this action pulls the sleeve material back from the area of thelips 21. This in turn reduces friction between the downwardly movinggate, which is slidably guided between seat end faces 22′, and theopposing lips 21′. Accordingly, the stiffener ring 100 provides for goodsmooth reduced friction sliding contact between opposing sleeves 20′ andthe gate 16.

The inner and outer surfaces 28′, 30′ of the wall 32′ initiate from theflange end face 19′. The flange end face 19′ is preferably substantiallyperpendicular to the central axis A-A for engagement with the flangeface of another piping element in the piping assembly. Referring againto FIG. 5B, the flange end face 19′ includes an outer perimeter 15′ andan inner perimeter 13′ to define the opening to the central passageway14′. The flange face 19′ defines a preferably annular or ring shapedplanar surface with the inner and outer perimeters 13′, 15′ beingsubstantially circular and respectively defining an inner diameter IDand an outer diameter OD with a center point that is collinear with thecentral axis of the passageway 14′. Alternatively, the inner and outerperimeters 13′, 15′ can be any geometry such as, for example,rectangular or polygonal provided the flange end face 19′ can engage theflange surface of the valve housing 12 and material can flow throughpassageway 14′ of the valve sleeve 20.

The inner and outer surfaces 28′, 30′ extend axially from the flange endface 19′ to define the flange portion 24′. The outer surface 28′ alongthe flange portion 24′ preferably defines a first shelf 42′ and furtherpreferably defines a second shelf 44′. The first shelf 42′defines atransition from the flange portion 24′ to the seat portion 26′ in theunitary construction of the valve sleeve 20′ and further defines anaxial thickness of the flange portion 24′ to engage a recess or othersurface of the flange face in the housing 12.

The second shelf 44′ defines an axial thickness of flange portion 24′that is different and preferably less than the axial thickness definedby the first shelf 42. The second shelf 44′ is preferably circumscribedabout the first shelf portion so as to further define a gasket portion11′ of the flange portion 24′. The gasket portion 11′ is preferably ofsuch an axial thickness so as to provide an adequate seal to the valve10 in a piping assembly and thereby eliminating the need for a separategasket material. Accordingly, the gasket portion 11′ is preferablyconfigured such that the flange portion 24′ can be radially aligned withthe bolt hole pattern of the housing 12. Thus, the gasket portion 11′preferably includes one or more radially disposed scallops or voids 17′,as seen in FIG. 5 to trace the bolt hole pattern of the housing 12. Thegasket portion 11′ can provide a seal between the valve 10 and anadjacent piping element thereby eliminating the need for a separategasket element. Moreover, the gasket portion 11′ can be configuredindependent of the pipe size to which the valve is to be coupled. Theinventor has discovered in a 5,000 cycle test of the valve 10 and sleeve20′ in a piping assembly, that a complete seal is achieved whenapplying, at a minimum, 35-40 ft-lbs of torque at the flange bolts.Known sleeves using the two-piece sleeve design with support disc mayrequire as much as 100-125 ft-lbs of torque to create an adequate seal.

To resist overcompression of the flange portion 24′ of the valve sleeve20′ when the valve 10 is coupled to another element, the flange portion24′ is configured to define another chamber 46′ as seen for example inFIG. 5B. The chamber 46′ is preferably disposed between the innersurface 30′ and the outer surface 28′ so as to be completely enclosedwithin the wall 32′. More preferably, the chamber 46′ is locatedproximate of the first shelf 42′ so as to locate the chamber 46′ withinthe recess of the flange face 18 of the housing 12 when the valve sleeve20′ is installed. The chamber 46′ extends axially preferably to a pointproximal of the first shelf 44′ such that the chamber 46′ is locatedcompletely within the flange portion 24′ of the sleeve 20′.

The chamber 46′ is configured so as to house, or more preferably encase,a substrate within the flange portion 24′ to provide a stiffeningelement for providing axial support and/or compressive resistance to,for example, the compressive force exerted by the flange bolts couplingthe valve 10 to the piping assembly. Preferably, the chamber 46′ iscontinuous about the central axis of the passageway 14′ so as to definea ring for housing a ring shaped substrate. Alternatively, the chamber46′ can be any other geometry such as, for example, rectangular orpolygonal for housing a correspondingly shaped substrate. Further in thealternative, a plurality of chambers radially disposed about the centralaxis and within the flange portion 24′ can be provided for housing aplurality of stiffening elements.

The chamber 46′ is preferably substantially ring shaped having arectangular cross-section for encasing the ring shaped substrate orplate 200 as seen in FIG. 8. The plate 200 defines an inner diameter andan outer diameter each preferably dimensioned such that the plate 200can be completely housed within the chamber 46′ of the valve sleeve 20′.In one example in which the valve sleeve 20′ is configured for a nominalsix inch valve, a preferred plate 200 has an outer diameter of abouteight inches, an inner diameter of about six inches, more preferably 6.3inches and a uniform thickness of about three-sixteenths of an inch (3/16 in.). The plate 100 is preferably made of steel such as, forexample, HRMS ASTM 36, stainless or other suitable steel. Alternatively,the plate 100 can be made from any other material capable of providingthe compressive strength and axial support to the flange portion 24′ ofthe valve sleeve 20′.

Referring again to FIG. 5, the flange end face 19′ of the valve sleeve20′ can include one or more openings 50′ radially spaced from thecentral axis. Preferably, the opening 50′ is substantially circularalthough other geometries such as, for example, rectangular or otherpolygonal shapes are possible. As seen in FIG. 5B, the wall 32′ furtherdefines at least one axially extending third chamber 52′ disposedbetween the outer and inner surfaces 28′ and in communication with theopening 50′. The third chamber 52′ is preferably substantiallycylindrical having a circular cross-sectional area along a central axispreferably parallel to and radially spaced from the central axis A-A.The chamber 52′ extends distally from the flange end face 19′ andpreferably extends from the flange portion 24′ into the seat portion26′, terminating proximal of the seat end face 22′. Where first andsecond chambers 33′, 46′ continuously circumscribe the central axis A-Aof the passageway 14, the third chamber 52′ is preferably incommunication with the first and second chambers 33′, 46′.

The valve sleeve 20′ can include a plurality of chambers 52′ each havingan opening 50′ equiradially disposed about the central axis A-A. Forexample, as seen in FIG. 6, the sleeve 20″ can have sixteen chambers 52″spaced apart by about 22.5°) or alternatively, the sleeve 20′ can havefour chambers 52′, as seen in FIG. 5, each spaced apart by about 90°.Preferably, the number of chambers is minimized so as to minimize thestress concentrations in the sleeve 20′ around the edges defining thechambers 52′. As with known valves, the number of chambers 52′ may varywith the nominal size of the valve. Alternatively, a relationshipbetween the total volume of the chambers 52′ and the total volume of thesleeve 20′ can be provided without regard to valve size.

A pin plug 60 can be provided, for example as seen in FIG. 5C, forinsertion into one or more of the chamber 52′ to provide additionalsupport to the sleeve 20′ and further minimize the presence or effect ofany stress concentrations. More preferably, every chamber 52′ issubstantially filled with the pin plug 60. The pin plug 60 is preferablya cylindrical axially extending member having a base end 61′ dimensionedso as to substantially fill the cross-sectional area of an opening 50′in the flange end face 19′. The pin plug 60 further includes aninsertion end 62 for locating the pin plug 60 within the chamber 52′.The insertion end 62 is preferably dimensioned such that the pin plug 60tapers in the axial direction narrowly from the base end 61. Moreover,the insertion end 62 is preferably axially spaced from the base end 61such that the pin 60 substantially fills the chamber 52′. Preferably,the pin 60 does not axially extend into the first chamber 33′ of thewall 32′. The insertion end 62 can further include an extension 63 so asto axially extend and completely fill the chamber 52 yet avoidintersecting the first chamber 33′. Preferably, the extension 63 definesa semi-circular cross-section, as seen in FIG. 5D, to substantially fillthe portion of chamber 52′ located between the first chamber 33′ and thewall 32′ and thereby frame the chamber 33′. The pin 60 is preferablymade of a rubber material and can further be made of a materialssubstantially similar to the wall 32′ of the valve body 20′.Accordingly, the pin 60 preferably is of a durometer substantiallysimilar to the wall 32′ or can alternatively be harder or softer thanthe wall 32′. Further in the alternative, the pin 60′ can be made from aplastic, resilient closed cell foam, or any other material capable ofbeing formed into the pin 60 and further being capable of supporting thesleeve 20.

As noted, the valve sleeve 20′ is of a unitary or one-piece constructionfor insertion into a valve housing 12. Preferably, the valve sleeve 20′is made by a molding process that includes transfer or compressionmolding, and more preferably includes injection molding. To form thevalve sleeve 20′, the stiffening elements ring 100 and plate 200 arelocated within a mold 300 and an elastomeric material introducedtherein. The material is permitted to cure and set to form the valvesleeve 20′.

Shown in FIG. 9 is a plan view of a mold 300 for forming valve sleeve20. The mold 300, as seen in cross-section in FIG. 9A, includes an innersurface defining a chamber 302 having a central axis, a center or coremember 304 axially extending through the chamber 302 along the centralaxis, and at least one input port 305 in communication with the chamber302 for introducing an elastomeric material into the chamber 302 to formthe valve sleeve body 20′ by way of transfer or compression molding andmore preferably by way of injection molding. The inner surface of themold 300 is preferably circular cylindrical and the center member 304 isalso preferably circular cylindrical such that the chamber 302 issubstantially annular or ring-shaped. The inner surface of the mold 300and the center member 304 are contoured so as to define respectively theouter surface 30′ and inner surface 28′ of the valve sleeve 20′ duringvalve sleeve formation. More specifically, the inner surface of the mold300 and the center member 304 are contoured so as to define the outerand inner surfaces of the flange portion 24′ and the seat portion 26′ ofthe valve sleeve 20′ as described above. As seen in FIG. 9B, the innersurface of the mold 300 which defines the chamber 302 outlines the wall32′ of the sleeve 20′.

The mold 300′ preferably includes a bottom plate 306, a center plate 308and a top plate 310 axially coupled together and centrally aligned alonga central axis so as to form the inner surface of the mold 300 anddefine the chamber 302. The center member 304 can be coupled to the mold300 and introduced into the chamber 302 or more preferably engages acentral recess formed in the bottom plate 306.

To form the valve sleeve 20′, stiffening elements or substrates arelocated within the chamber 302 prior to encapsulation by the elastomericmaterial. More specifically, the ring 100 is disposed within the portionof the chamber 302 that is to form the seat portion 26′ and the ringplate 200 is disposed within the portion of the chamber 302 that is toform the flange portion 24′. To locate the ring 100 and the ring plate200 in the chamber 302, the mold 300 includes one or more location pins312 radially disposed about the center member 304. Preferably, asufficient number of location pins 312 are radially disposed about thecenter member 304 so as to circumscribe the center member 304. The baseplate 314 engages the bottom plate 306 such that the location pins 312are aligned and inserted through the pin holes of the base plate 306 andcircumferentially located about the center member 304.

The location pins 312 are preferably substantially cylindrical memberseach extending axially parallel to the center member 304. The locationpin 312 is dimensioned and configured to engage the ring plate 304 so asto axially and radially locate the ring plate 304 within the portion ofthe chamber 302 shaping the flange portion 24′ of the valve sleeve 20′.Referring to FIG. 8, the ring plate 200 preferably defines one or morevoids 210. The voids 210 are substantially circular to correspondinglyengage the location pins 312. The location pins 312 and voids 210 candefine any geometry provided the plate 200 and location pins 312 canengage one another. In forming the sleeve 20′, the ring plate 200 isaligned with one or more available location pins 312 such that anyavailable location pin 312 is inserted through an available void 210.Because the locations pins 312 preferably circumscribes the centermember 304 of the mold, the ring plate 200 is accordingly centered aboutand circumscribes the center member 304.

The location pins 312 are also preferably configured to radially locatethe ring 100 about the center member 304 and within the seat portion ofthe valve sleeve 20′. As seen in FIG. 9B, the location pins 312preferably include at one end a notch 313 which is located within thechamber 302 that forms the seat portion 26′ of the valve sleeve 20′. Thenotch 313 preferably forms a right angle having a vertical surfaceparallel to the central axis of the mold 300 and a horizontal surfaceperpendicular to the central axis. In forming the valve sleeve 20′, thering 100 is disposed over the location pins 312. The ring 100 isdimensioned and configured so as to engage the vertical and horizontalsurfaces of the notch 313, thereby centrally aligning the ring 100 withand circumscribing ring 100 about the center member 304.

The mold 300 is preferably configured to also properly axially align thering 100 and the ring plate 200 respectively within the seat portion 26′and the flange portion 24′. To facilitate the proper axial location ofthe ring 100 and ring plate 200, the base plate 314 preferably includesprings (not shown) which engage the bottom plate 306. The springs allowfor the axial displacement of the location pins 312 relative to theremainder of the mold 300 during the molding process. In a preferredmethod of injection molding the valve sleeve 20′, the assembled mold300, with the ring 100 and ring plate 200 located in the chamber 302, asdescribed above, is placed in a press which compresses the springs ofthe base plate 314 and axially translates the location pins 312 relativeto the chamber 302. The axial translation of the location pins 312properly axially locate the ring 100 and the ring plate 200 within thechamber 302 so that upon introduction of the elastomeric material intothe mold 300 the ring 100 and the ring plate 200 are respectivelyproperly encased in the seat portion 26′ and flange portion 24′ of thevalve sleeve 20′.

The valve sleeve 20′ is formed such that the both the ring 100 and thering plate 200 are fully encased in elastomeric material. Preferably,the input port 305 of the mold 300 is located in the top plate 310 suchthat the elastomeric material is injected into the mold 300equiradially. More specifically, the input port 305 is preferablyaligned with the central axis of the mold 300 such that the elastomericmaterial is distributed substantially evenly 360°) about the centermember 304.

To facilitate the encasement of the substrate members 100, 200, the ring100 and ring plate can be configured for distributing the elastomericmaterial throughout the mold. For example, again referring to FIG. 8,the ring plate 200 can include one or more voids 212 disposed betweenpin engaging voids 210. Voids 212 are preferably triangular shaped tofacilitate the flow of elastomeric material about the ring plate 200 andthroughout the chamber 302. More specifically, the voids 212 providegreater surface area to the ring plate 200 over which the elastomericmaterial entering the chamber 302 can be introduced and encapsulate.

Although the mold 300 can be configured for compression or transfer moldprocessing, the inventor has discovered that using the mold 300 in aninjection mold process can reduce the time to sleeve formation overtransfer or compression molding by over ninety percent. For example,where compression or transfer mold processing to form a nominal six inchvalve sleeve 20′ may take about forty-five to about fifty minutes, thesame sleeve 20′ may require about four to five minutes. Followinginjection of the elastomeric material into the mold 300 and furtherfollowing an appropriate set time, the valve sleeve 20′ is molded andformed as the above-described one-piece construction. The mold sleeve20′ is then removed from the mold. The location pins 312 separate fromthe elastomeric material thereby defining the opening 50′ in the flangeportion 24′ and the axially extending chamber 52′ in the wall 32′.Remaining fully encapsulated in the valve sleeve 20′ are the ring 100and the ring plate 200.

A finishing process is applied to the molded valve sleeve 20′ to preparethe piece for use in a valve 10. The preferred injection process mayleave behind elastomeric material in the passageway 14′ of the sleeve20′. The excess material is preferably removed and the inner surface 30′of the sleeve 20′ is treated so that the passageway 14′ has a smoothsurface over which material may flow. Any suitable elastomeric materialcan be used to form the valve sleeve such as, for example, naturalrubber so long as the material is capable of being used in the moldingprocess. Preferably, the material utilized in forming the sleeve isselected so as to be well suited for the environment in which the valve10 is to be employed. Accordingly, depending upon the application ofuse, appropriate elastomeric materials for forming the sleeve 20′include but are not limited to: gum rubber, EPDM-HTP, Nitrile andNitrile-HTP, Hypalon, and Fluoroelastomer. Moreover, because the sleeve20′ is preferably constructed from a homogenous material, the valvesleeve 20′ tends to have substantially the same chemical resistantqualities throughout.

FIG. 10 illustrates a perspective view of an alternative embodiment ofvalve sleeve 400 having a flange portion 424 and a seat portion 426.Valve sleeve 400 has a unitary construction to provide a one-piecesleeve for use with new or existing valves 10. Similar to the sleeveillustrated in FIG. 5, sleeve 400 is preferably made of an elastomericmaterial which allows the seat portion 426 to be elastically resilientto the stress forces applied by gate 16 (shown in FIGS. 3 and 4) andfurther enables the flange portion 424 to be resilient to thecompressive forces exerted by the flange bolts or other coupling deviceholding valve 10 within the pipe assembly. Valve sleeve 400 is generallyan annulus or other ring shaped body having an outer surface 428 forengaging the valve housing 12 and an inner surface 430 to define apassageway 414 therethrough having a central axis A-A. The outer surface428 along the flange portion 424 defines a radial distance from thecentral axis A-A that is preferably greater than the radial distancedefined by the outer surface along the seat portion 426 relative to thecentral axis A-A.

FIG. 10A illustrates a cross-sectional view of the sleeve 400′ and FIG.10B illustrates a detailed cross-sectional view (identified as B in FIG.10A) of a wall of the valve sleeve. The outer and inner surfaces 428,430 define an annular wall 432 which is preferably radially spaced andcircumscribed about the central axis A-A of passage 414 to form the bodyof the valve sleeve 400. Wall 432 has homogeneous material propertiesand includes flange portion 424 having a flange end face 419 where wall432 axially extends to seat portion 426 and terminates at a distalsecond end portion with seat end face 422. The outer surface 428 alongseat portion 426 of wall 432 is preferably configured to be insertableinto existing valves. More specifically, seat portion 426 preferablyincludes lip portion 421 at the end of the valve sleeve to engage aninterior groove within valve housing 12 to secure the valve sleeve inthe sleeve recess of the housing 12. The lip portion 421 preferablyincludes a locking bead or ridge 423 disposed along the seat portion 426which is preferably located at approximately the midpoint of the lengthL of valve sleeve 400 and more specifically at about 53% of length Lmeasured from the flange end face 419. The ridge 423 defines a radialoutermost portion of wall 432 along seat portion 426 and is configuredfor engaging a recess within housing 12 to support the valve sleeve 400therein. The ridge 423 can be configured to prevent the sleeve 400 fromfalling out of the housing 12 when the valve 10 is not installed in thepipe assembly and can prevent slurry or other material buildup that maymigrate between the valve sleeve and the housing.

Distal from ridge 423, lip portion 421 radially tapers toward thecentral axis A-A and has a first tapering portion 425 and a secondtapering or angled portion 427. The first tapering portion 425 defines afirst angle a relative to a line parallel to the central axis of thepassageway 414 and the second tapering or angled portion 427 defines asecond angle β relative to an angle perpendicular to the central axis ofpassageway 414. Preferably, the first angle α is about five degrees (5°)to about fifteen degrees (15°) and is more preferably about ten degrees(10°. The second angle β is preferably about fifteen degrees (15°) toabout twenty-five degrees (25°) and is more preferably about twenty-oneto twenty-three degrees (21°-23°).

The outer surface 428 defines a continuous transition with the innersurface 430 of wall 432 to further define lip portion 422. Inparticular, angled portion 427 is continuous with a first curved portion434 which is preferably convex relative to passageway 414 to define acurved surface for engaging a corresponding portion of an opposingsleeve 400 when valve 10 is an open position or flow control gate 16when valve 10 is in a closed position or in the process of closing. Theconvex curved portion 422 defines a radius of curvature ranging betweenabout 0.15 inches to about 0.25 inches and more preferably is about 0.19inches Inner surface 430 includes a second curved portion 436 and athird curved portion 438 continuous in series with first curved surface434 to define a groove 436′ along the inner surface 430. The curvedsurfaces can be configured as concave or convex relative to thepassageway 414 with a particular radius of curvature depending on thesize of valve 10. For example, second curved surface 436 may be concavewith a radius of curvature of about 0.130 inches and third curvedsurface 438 may be concave also with a radius of curvature of about0.130 inches. The curved surfaces 436, 438 define the radial groove 436′along the inner surface 430 that acts as a spring for sleeve 400 whengate 16 is in a closed position or when gate 16 is in the process ofclosing. Radial groove 436′ may have a radius of curvature, for example,of approximately 0.109 inches. As can been seen, redial groove 436′ islarger as compared to the redial groove formed by curved surfaces 36′and 38′ shown with respect to the embodiment of FIG. 5B and curvedsurfaces 36″ and 38″shown in FIG. 6B. In particular, when gate 16 passesfirst curved surface 434, gate 16 applies forces against wall 432 andcompresses wall 432 in directions x and y. The radial groove 436′provides a rebound or spring-like effect in sleeve 400. Moreover, in theabsence of radial groove 436′, the compressive forces applied by gate 16would force wall 432 and curved surface 434 into the path of gate 16toward direction x and/or in direction y against the respective half ofhousing 12 in which sleeve 400 is engaged. Thus, the radial groove 436′provides a cavity or space in which the portion of wall 432 compressesas gate 16 passes sleeve 400.

Similar to the embodiments disclosed with reference to FIGS. 5 and 6, achamber 433 is located between the inner surface 428 and outer surface430 of wall 432. Chamber 433 is located within the lip portion 421 ofseat portion 426 and more preferably located distal of ridge 423. Inaddition, chamber 433 is radially closer to outer surface 428 than toinner surface 430. Where the dimension T is the radial distance betweenthe outer surface 428 and the inner surface 430, the radial spacingbetween the chamber 433 and the outer surface 428 has been found to beabout 11.5% of thickness T for all nominal sizes of valve sleeve 400. Inaddition, where the axial distance between flange end face 419 to theseat end face 422 is length L, the axial distance from flange end face419 to about the center point of the cross-sectional area of chamber 433is about 65% of the length L. Chamber 433 is continuous about thecentral axis A-A of the passageway 414 and defines a ring chamber havinga substantially circular cross-section for housing a tubular ring shapedsubstrate or stiffening element. This stiffening element provides radialresistance to, for example, shearing forces exerted by gate 16 on thevalve sleeve 400 as gate 16 travels between the open and closedpositions. Although chamber 433 is described as having a substantiallycircular cross-section, other geometries may also be employed. FIG. 7illustrates a stiffener ring 100 that may be housed within chamber 433.As described with reference to FIG. 7, stiffener ring 100 providesradial support for ridge 423 and prevents the pliable sleeve materialfrom following gate 16 during its open and closing cycle. In addition,stiffener ring 100 can facilitate alignment of opposing sleeves 400installed in valve housing 12.

Returning to FIG. 10B, the inner surface 430 and outer surface 428 ofwall 432 initiate from flange end face 419. The flange end face 419 ispreferably substantially perpendicular to the central axis A-A forengagement with the flange face of another piping element in the pipingassembly. Flange face 419 defines an annular or ring shaped planarsurface with an inner perimeter point defined by inner surface 430 andan outer perimeter defined by outer surface 428 being substantiallycircular and respectively defining an inner diameter ID and an outerdiameter OD with a center point that is collinear with the central axisof the passageway 414. The inner surface 430 and outer surface 428extend axially from the flange end face 419 to define the flange portion424. The outer surface 428 along the flange portion 424 defines a firstshelf 442 and a second shelf 424 a. First shelf 442 defines a transitionfrom the flange portion 424 to seat portion 426 in the unitaryconstruction of the valve sleeve 400 and further defines an axialthickness of the flange portion 424 to engage a recess or other surfaceof the flange face within housing 12. Second shelf 424 a defines atransition from first shelf 424 to flange face 419. A first o-ring 451 ais positioned toward inner surface 430 circumferentially around sleeve400 and a second o-ring is positioned toward outer surface 428circumferentially around sleeve 400, where each of the o-rings provide aseal with housing 12. These o-rings replace the gasket portion 11′ shownin FIG. 5B and can be configured to provide a seal when the valve iscoupled to a piping system. These o-rings provide sealing effect with aslittle as 15 ft-lbs depending on size and the type of elastomericmaterial employed and 35-40 ft-lbs of torque at the flange boltlocations of a piping assembly.

To resist over-compression of flange portion 424 when valve 10 iscoupled to a process pipe, chamber 446 houses a stiffening elementenclosed within wall 432. In particular, chamber 446 is locatedproximate shelf 442 and extends axially to a point proximal the firstshelf such that chamber 446 is located completely within flange portion424 of sleeve 400. Chamber 446 is configured to house a ring shapedsubstrate having a generally rectangular cross-section similar to plate200 shown in FIG. 8. As noted earlier, the plate acts as a stiffeningelement and provides axial support and/or resistance to the compressiveforce exerted by, for example, the flange bolts coupling the valve 10 toa process pipe assembly. Chamber 446 is continuous about the centralaxis of the passageway 414 to define a ring for housing the ring shapedstiffening element and/or a plurality of stiffening elements. Plate 200is depicted in FIG. 8 with a plurality of voids 210, 212 configured toprovide mechanical bond with sleeve 400 during the molding thereof. Byway of example, a valve sleeve 400 configured for a nominal six inchvalve, plate 200 would have an outer diameter of about eight inches, aninner diameter of about six inches, more preferably 6.3 inches and auniform thickness of about 0.135 inches.

Referring again to FIG. 10B, wall 432 further defines at least oneaxially extending third chamber 452 disposed between the outer surface428 and inner surface 430 and in communication with opening 450 (shownin FIG. 10C) at certain points around sleeve 400. The third chamber 452is substantially cylindrical having a circular cross-sectional areaalong a central axis parallel to and radially spaced from the centralaxis A-A. The chamber 452 extends distally from the flange end face 419and extends from the flange portion 424 into seat portion 426,terminating proximal of the seat end face 422. Where first chamber 433and second chamber 446 continuously circumscribe the central axis A-A ofthe passageway 414, third chamber 452 communicates with the firstchamber 433 and second chamber 446. Third chamber 452 is used during themolding process to position stiffening ring 100 within first chamber433. In particular, third chamber 452 has an extension portion 452 athat extends toward angled portion 427 to a point approximately at thecentral axis of first chamber 433. By comparison, third chamber 52′shown in FIG. 5B has an upper portion which extends beyond first chamber433. The reduced dimension of extension portion 452 a as shown in FIG.10B provides a smaller chamber within which a plug, such as plug 60shown in FIGS. 5C and 5D is positioned while still providing adequatepositioning access for stiffening element housed in first chamber 433. Apin plug, similar to that shown in FIGS. 5C and 5D is positioned withinchamber 452 after the stiffening ring has been molded within sleeve 400.Pin plug 60 provides additional support to the sleeve 400 and furtherminimize the presence or effect of any stress concentrations. However,because extension portion 452 a of third chamber 452 is shorter than thecorresponding portion of chamber 32′ shown in FIG. 5B, the extensionportion 63 of plug 60 would likewise be shorter for a plug positionedwithin third chamber 452. In addition, plug 60 is configured such thatthe extension portion 63 avoids intersecting first chamber 433 whilestill providing additional support within the third chamber 452.Otherwise, base end 61 and insertion end 62 of plug 60 shown in FIGS. 5Cand 5D is substantially the same as a plug used for insertion in chamber452.

FIG. 10C is a back plan view of valve sleeve 400 showing flange portion424 having one or more openings 450 spaced around sleeve 400. Eachopening 450 is substantially circular and extends into cylindrical thirdchamber 452 to provide a means for locating the support ring housed inchamber 452 and to locate the support plate in chamber 446. A firsto-ring 451 a extends circumferentially around sleeve 400 and secondo-ring 451 b extends circumferentially around sleeve 400. Sleeve 400further includes voids 412 spaced around sleeve 400 which are used tosupport the plate housed within chamber 446 during the molding process.The description of openings 450 and voids 412 are described above withreference to FIGS. 9, 9A and 9B and the associated detailed description.The pin plug 60 is provided for insertion into one or more of thechambers 452 via openings 450 to provide additional support to thesleeve 400 and further minimize the presence or effect of any stressconcentrations. The pins 60 are preferably made of a rubber materialand/or materials substantially similar to the wall 432 of sleeve 400. Ithas been found that plugs 60 made of plastic and like material aresusceptible to cracking during valve operation thereby exposing theinterior of sleeve 400 to process media. Moreover, the mold 300 shown inFIG. 9 to form the sleeve 20′ is different from the mold used to formsleeve 400. In particular, the springs used in embodiment of FIG. 9which allow for the axial displacement of the location pins relative tothe remainder of the mold during the molding process are not used inthis alternative embodiment.

While the present invention has been disclosed with reference to certainembodiments, numerous modifications, alterations and changes to thedescribed embodiments are possible without departing from the sphere andscope of the present invention, as defined in the appended claims.Accordingly, it is intended that the present invention not be limited tothe described embodiments, but that it has the full scope defined by thelanguage of the following claims, and equivalents thereof.

1. A sleeve for sealing a gate valve, the sleeve comprising: a body ofunitary construction defining a flange portion configured to engage avalve housing and a sealing portion configured to engage a gate portionof said valve, said body having a generally circular shape defining anaxially extending passage therethrough, said body having an inner walland an outer wall; a first curved surface of said inner wall extendingaround said sealing portion, said first curved surface configured toengage said gate portion of said valve; a second curved surface of saidinner wall contiguous with said first curved surface, said second curvedsurface extending around said inner wall, said second curved surfacebeing concave relative to said body a radial groove defined by saidconcave second surface, said radial groove configured to provide aspring-like force biased against said gate portion of said valve; and atleast one support member encapsulated in the body between the innersurface and the outer surface, the member having a surface radiallyextending in a direction from the inner surface to the outer surface soas to substantially support said sealing portion in an axial direction.2. The sleeve of claim 1 wherein said support member is housed within achamber extending circumferentially within said body.
 3. The sleeve ofclaim 2 wherein the support member is a first support member and thebody includes a second support member spaced axially from the firstsupport member.
 4. The sleeve of claim 3 wherein said chamber is a firstchamber, said second support member is housed within a second chamberextending circumferentially within said body, said second support memberconfigured to support said flange portion.
 5. The sleeve of claim 4further comprising a third chamber extending from said second chamber tosaid first chamber.
 6. The sleeve of claim 5 wherein said third chambercontinuously circumscribes said passage within said sealing portion. 7.The sleeve of claim 1 wherein the flange portion includes at least oneopening in communication with said third chamber in the body extendingin the axial direction.
 8. The sleeve of claim 4, further comprising apin plug disposed in the second chamber.
 9. The sleeve of claim 5,further comprising a pin plug disposed in the third chamber.
 10. Thesleeve of claim 1 further comprising a lip portion disposed along saidseat portion toward said outer wall, said lip portion configured toprovide a sealing engagement with a portion of said valve.
 11. Thesleeve of claim 1 wherein said body is formed from an elastomericmaterial.
 12. The sleeve of claim 8 wherein said body and said pin areformed from an elastomeric material.